Teratoma diagnosis reference standard

It is generally believed that teratomas are mostly formed in the early stage of individual development, when some pluripotent primitive cells are separated and proliferate in the mediastinum to develop into tumors. Benign teratomas are the most common tumors of this type. They are often located in the anterior mediastinum. Teratomas are mostly solid, and there may be cysts of varying sizes, containing derivatives of external and pelvic teratomas or endodermal tissues such as hair, teeth, cartilage, smooth muscle, bronchial or intestinal wall.

Most teratomas are exophytic or have palpable masses, and early diagnosis is often possible based on clinical manifestations. A careful abdominal physical examination and rectal digital examination with pulmonary teratoma angiography are necessary for the examination of abdominal, pelvic, and occult sacrococcygeal teratomas. X-rays of the tumor site can reveal abnormal calcifications of bones, teeth, etc. in the tumor to confirm the teratoma, which is mostly mature teratoma. Gastrointestinal barium meal, barium enema, and intravenous pyelography can understand the compression and displacement of the corresponding gastrointestinal tract or organs such as the kidneys, ureters, and bladder.

CT and MRI examinations should be performed on teratomas that grow rapidly and have a wide range of infiltration to clarify the range of tumor infiltration and its adjacent relationship with important blood vessels and spinal nerves.

If a malignant teratoma is considered, the serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) levels should be tested for diagnosis and prognosis. 92% of malignant teratomas have elevated alpha-fetoprotein, while 4% of benign teratomas have abnormal AFP. It was found that patients with elevated AFP in benign teratomas had a significantly increased recurrence rate after surgery.

Spine X-rays show a large or obvious widening of the intervertebral cavity, narrow pedicles at the site of the lesion, widened interpedicular distance, concavity of the posterior edge of the vertebral body, and in some cases, manifestations of spina bifida.

CT and MRI have obvious advantages in diagnosing teratomas, and both can better show the heterogeneity of tumors. On MRI images, teratomas appear as mixed signals, often with intact cyst walls, rich in fat signals, with or without intratumoral enhancement nodules, and usually, in addition to the tumor, are often accompanied by spina bifida or vertebral dysplasia.